Overview
• Android is a software stack for mobile devices that includes an
operating system, middleware and key applications.
• Android OS is divided into five sections
• Applications: This is where applications to be installed are written. E.g. Games,
Browser etc.
• Application Framework: This layer provides many higher-level services to
applications in the form of Java classes.
• Android Runtime: This section provides a key component called Dalvik Virtual
Machine. Dalvik VM enables every android application to run in its own process, with
its own instance of the Dalvik VM. Dalvik VM is optimised to run on slow CPU, low
RAM, low power devices. It runs .dex files and not .class nor .jar
• Libraries: e.g. SQLite database, repository for storage and sharing of application.
• Linux Kernel : it provides basic system functionality e.g. process management,
device management etc.